Noun

(en noun)

A smaller, self-contained part of a larger entity. Often refers to a manufactured object that is part of a larger device.

* {{quote-magazine, year=2013, month=September-October, author= Katie L. Burke

, magazine=(American Scientist), title= In the News , passage=Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis:

Noun

(en noun)

A device used to produce music.

The violinist was a master of her instrument .

A means or agency for achieving an effect.

* {{quote-book, year=1905, author=

, title= , chapter=1 citation , passage=“There the cause of death was soon ascertained?; the victim of this daring outrage had been stabbed to death from ear to ear with a long, sharp instrument , in shape like an antique stiletto, which […] was subsequently found under the cushions of the hansom. […]”}}

A measuring or displaying device.

The instrument detected an increase in radioactivity.

A tool, implement used for manipulation or measurement.

The dentist set down his tray of instruments'''.'' The scientist recorded the temperature with a thermometer but wished he had a more accurate ' instrument ."

(legal) A legal document, such as a contract, deed, trust, mortgage, power, indenture, or will.

A bond indenture is the instrument that gives a bond its value.

Negotiable instruments are the foundation of the debt markets.

(figuratively) A person used as a mere tool for achieving a goal.

* Shakespeare

Or useful serving man and instrument , / To any sovereign state.

* Dryden

The bold are but the instruments of the wise.